How much electricity does my computer use? 3
The university I work at has started to implement many energy saving processes into its business environment. One includes powering down monitors during the day when the computer is not in use. Why this feature wasn’t already set up, I don’t know. But in any case, my network admin estimates it will save the university thousands of dollars per year by doing this.
Thinking on this, I decided to check out how much my own computer was draining my wallet. I leave it on pretty much 24/7.
The answer? I didn’t know Macs are so power-friendly compared to PCs. And I never really thought about the formula for calculating how much it costs to power your computer for a year.
(Watts)x(Hours Used)/1000 x Cost per kilowatt-hour = Total Cost
“For example, let’s say you have a big high-end computer with a gaming-level graphics card and CRT monitor, and you leave them on 24/7. That’s about 330 watts x 24 hours x 365 days/yr = 2,890,800 watt-hours, or 2891 kilowatt-hours. If you’re paying $0.14 per kWh, you’re paying $405 a year to run your computer.
Let’s try a different example: You have a computer that’s less of an energy hog, like in iMac G5 20″, which uses about 105 watts, and you’re smart enough to turn it off when you’re not using it. You use it for two hours a day, five days a week. That’s ten hours a week, or 520 hours a year. So your 105 watts times 520 hours = 54,600 watt-hours. Divide by 1000 and you have 55 kilowatt-hours (kWh). If you’re paying 10ยข per kilowatt-hour, then you’re paying $5.50 a year to run your computer.”